﻿154 Dr. Emil Paulson on the 



By applying the same method to the approximation con- 

 taining a fourth power of a, I find that an approximate 

 solution is given by 



7 o 9 2 . (I - a) 2 **' 4 



where a is chosen to have a value slightly less than unity, 

 and b is then determined by 



6 3 /47ic 2 =a(l - a) + (1- a) 2 /a. 



The steps are laborious, and it is not necessary to reproduce 

 them. The solution is the oval of a quartic curve (which 

 also possesses imaginary parabolic branches). It is clearly 

 slightly less eccentric than the approximate elliptic solution. 

 It is nearer the truth, inasmuch as the steps leading to it 

 involve the neglect of terms in (1— a) 3 and higher powers, 

 whereas the elliptic solution neglected terms in (1 — a) 2 . 



XVI. On the Spectrum of Palladium, 



By Dr. Emil Paulson *. 



KAYSER t was the first to show the existence of triplets 

 in the spectrum of Palladium. This was found by 

 him to be repeated 6 times completely and 3 times in- 

 completely in the whole spectrum. Designating the 

 wave-number of the first line in each triplet by A and 

 those of the two other lines by B and C respectively, the 

 wave-numbers of the triplet are given by the relations : 



B = A + 3967-90 A 1 = 3967'90 



C = A + 5159-09 A 2 = 1191-19, 



A x and A 2 being the differences of the components of the 

 triplets. 



Afterwards, without being aware of the work of Kayser, 

 I % discovered the pairs with the difference 1191, but did 

 not find the complete triplet ; I also found many other pairs 

 with the differences 1628 and 403 respectively. It was, how- 

 ever, to be assumed that all these pairs and triplets could be 



* Communicated by the Author. 



t H. Kayser, " Die Spectren der Eleniente der Platingruppe," Abh. d. 

 Bert. Akad. 1897 : Astrophys. J. vii. 1899. 



% E. Paulson, " Beitriiffe zur Kenntnis der Linienspectren," "Diss, 

 Lund. 1914, pp. 33-34. 



